Leaves: Yellowish-green, with short fine hairs below, twice-divided (20–31 cm long), straight thorn at the junction of each of the 6–16 pairs of leaflet branchlets, each branchlet with 20–45 pairs of small elongated leaflets (3–12 mm long and 0.5–2 mm wide), leaves fold together at night or when touched.

Flowers: Pink or mauve, in fluffy round heads (1–2 cm wide), borne singly or in groups of two or three, on stalks (2–7 cm long), arising from each upper leaf fork.

Dense infestations of M. pigra contribute to a decline in abundance and diversity of species of plants and animals. In Tram Chim National Park, Vietnam, it has reduced the density of native plant species threatening the vulnerable sarus crane (Grus antigone L.) (Triet and Dung, 2001). M. pigra thickets in Australia had fewer plants, birds and lizards, than native vegetation (Braithwaite et al., 1989). In Lochinvar National Park, Zambia, infestations reduced bird diversity by almost 50% and abundance by more than 95% (Shanungu, 2009). In Cambodia, farmers ranked mimosa as the most significant problem affecting rice farming, ‘ahead of pests, rodents, and drought problems’ (Chamroeun et al., 2002). M. pigra also hampers fishing activities and prevents access to water bodies.

Source:

Witt, Arne. 2017. Guide to the Naturalized and Invasive Plants of Southeast Asia. CAB International. Retrieved from http://www.cabi.org/cabebooks/ebook/20173158961 on 23 October 2018